1. Field of the Invention
The present invention relates to rupturable pressure relief apparatus, and more particularly, but not by way of limitation, to a rupturable pressure relief apparatus of the type including at least one circular rupture disk supported between annular support members.
2. Description of the Prior Art
A great variety of rupturable pressure relief apparatus have been developed and used heretofore. Generally, such apparatus include a rupture disk clamped between inlet and outlet support members which are connected into a pressure relief system or area. When an overpressure condition exists in the system, the rupture disk ruptures and relieves pressurized fluids from the system through the apparatus.
The rupture disks which have been utilized have taken various forms and have included one or more parts. For example, flat rupture disks, rupture disks including concave-convex central portions and composites of such disks and other parts such as vacuum supports, support members, cutting members, etc., have all been utilized. Rupture disks with concave-convex central portions wherein the concave sides of the disks are exposed to fluids under pressure are commonly known as "conventional" rupture disks. Conventional rupture disks are placed in tension by the force of the fluids under pressure exerted thereon and rupture occurs when the tensile strength of the disk material is exceeded. Rupture disks including concave-convex central portions wherein the convex sides of the disks are exposed to fluid pressure are known as "reverse buckling" disks. Reverse buckling disks are placed in compression by the fluid pressure and upon rupture, the concave-convex portion first reverses itself and then ruptures.
Knife blades have been utilized with reverse buckling rupture disks to sever the disks upon reversal and bring about the full opening thereof without fragmentation, and scores or grooves have been utilized in both conventional and reverse buckling rupture disks to create lines of weakness therein whereby upon rupture the disks tear along the lines of weakness and fragmentation of the disks is prevented or substantially reduced.
While the various rupture disks and rupturable pressure relief apparatus developed heretofore have been used successfully in a variety of applications, in liquid service and in low pressure gas service problems have been encountered. More specifically, when conventional disks are utilized in such service which do not include scores or grooves creating lines of weakness therein, loose pieces are often formed upon rupture which can cause damage to or the malfunction of downstream apparatus. When conventional rupture disks having scores on a surface thereof or reverse buckling rupture disks including scores on a surface thereof or including knife blades for severing the disk are utilized in such service, fragmentation upon rupture of the disks is reduced, but often after initial rupture there is insufficient force exerted on the disk to open the disk fully.
By the present invention rupturable pressure relief apparatus which are non-fragmenting and which are particularly suitable for liquid and low pressure gas service are provided.